begin_download   CustDB 的 begin_download 脚本如下所示：

CALL ULOrderIDPool_maintain( {ml s.username} )

CustDB 的 ULOrderIDPool_maintain 过程如下所示：

ALTER PROCEDURE ULOrderIDPool_maintain ( IN syncuser_id INTEGER )
BEGIN
  DECLARE pool_count INTEGER;
  -- Determine how many ids to add to the pool
  SELECT COUNT(*) INTO pool_count
    FROM ULOrderIDPool
    WHERE pool_emp_id = syncuser_id;
  -- Top up the pool with new ids
  WHILE pool_count < 20 LOOP
    INSERT INTO ULOrderIDPool ( pool_emp_id )
      VALUES ( syncuser_id );
    SET pool_count = pool_count + 1;
  END LOOP;
END

download_cursor   CustDB 的 download_cursor 脚本如下所示：

SELECT pool_order_id FROM ULOrderIDPool WHERE last_modified >= {ml s.last_table_download} AND pool_emp_id = {ml s.username}

upload_delete   CustDB 的 upload_delete 脚本如下所示：

DELETE FROM ULOrderIDPool WHERE pool_order_id = {ml r.pool_order_id}